Re: [PATCH 2/3] KVM: x86: Save&restore interrupt shadow mask

Zachary Amsden
2010-02-17T08:06:16Z

On 02/16/2010 02:39 PM, Marcelo Tosatti wrote:
> On Mon, Feb 15, 2010 at 10:45:42AM +0100, Jan Kiszka wrote:
>
>> The interrupt shadow created by STI or MOV-SS-like operations is part of
>> the VCPU state and must be preserved across migration. Transfer it in
>> the spare padding field of kvm_vcpu_events.interrupt.

STI and MOV-SS interrupt shadow are both treated differently by
hardware. Any attempt to unify them into a single field is wrong,
especially so in a hardware virtualization context, where they are
actually represented by different fields in the undocumented but
nevertheless extant format that can be inferred from the hardware
virtualization context used by specific vendors.

Zach